Electronic products with a display function that are used currently, such as televisions, displays, digital cameras, mobile phones, PDAs, portable DVDs, etc, are each configured to display video signals with a liquid crystal panel, and the display effect of the liquid crystal panel is greatly dependent on the light source design and quality of a backlight module. The backlight module may directly affect the display effect and the image contrast of the liquid crystal panel, and therefore, the image display quality of the liquid crystal panel will be improved by providing the backlight module with a good performance.
In the fabricating process of the backlight module, it is necessary to defect whether the backlight module has a defect, such as scratch, foreign matter, stain, white spot, light leakage, etc. In a conventional detection method, the backlight module is firstly placed on a fixture and turned on, namely, the backlight module is lit, and then the backlight module is inspected by eyes of a worker. If there exits the defect, a marking is made at the defect location, and thereafter, the product with the defect is sent to a repair workshop. Since the above-described conventional detection method detects the defect in a manual manner, the work efficiency is low, the miss rate is relatively high, and accordingly this conventional detection method can not be applied to the mass production to achieve a satisfying quantitative detection.
In addition, if the backlight module is detected with an existing mechanical detection apparatus, only defects on the appearance of the backlight module can be detected and the defects inside the backlight module can not be detected.